Fluid operated mechanism



July ,12, 1932 R. H. THOMPSON FLUID OPERATED MECHANISM F'iled Nov. 24.1930 Patented July 12, 1932 UNITED STATES vPivrENTfoI-I-ICE ROBERTVH.THOMPSON, OF LOS ANGELES, CALIFORNIA, ASSIGNOR T0 LEO IM'.. HARVEY,

I 0F LOS ANGELES, CALIFORNIA FLUID OPERATED IVfIECHANISM Application ledNovember 24, 1930. Serial No. 497,796.

This invention relates to Huid operated mechanisms, andmorefparticularly to a fluid operated mechanism utilizing a relativelynon-compressible fluid for the purpose of driving a reciprocating motorpiston to which a pump is attached, the motor and pump being locatednear the foot of a well,-or example, an oil or like well, for the'purpose of aisilng the oil or similar fluid to the ground eveHeretofore many attempts have been made to provide a fluid operated pumpparticularly adapted for use in elevating oil from deep wells so as toenable the elimination of rods or mechanical connecting members commonlyemployed for the purpose of reciprocating such voil well pumps. v

A great many difiiculties are encountered in the use of such fluidoperated pumps due to many factors, including the presence ofia grittyor sandy fluid accompanying gas which must be elevated from the well toenable recovery of the oil content thereof.

Complicated structures operating on the principle of double-acting pumpsand provided with the necessary transfer ports have been'attempted buthave been unsatisfactory due to the fact that they can not be maintainedin operation under such conditions.

Many other forms of fluid actua-ted pumps have been suggested for use insuch deep wells which are dependent upon their operation to derive powerfrom the fluid being pumped as' it is alternately placed under pressureon the opposite sides of the piston of the driving motor. Such forms ofstructure have proven impracticable due to the high compressibility ofthe fluids being pumped which carry a high gas content enabling suchfiuids to be compressed to a relatively high degree without causing themotorto be operated.

The principal object of my invention is to provide a. fluid operatedmechanism which is of simple construction and which ,is operated by apair of columns of fluid so proportioned that the piston of the drivingmotor for such fluid operated mechanism is first driven downwardly by acolumn of relatively noncompressible fluid such, for example, as water7to which pressure may be applied without compressing the fluid, andwhich is then i driven upwardly by the static pressure of the columnoffluid being raised to the ground.

Another object of this invention is to prol vide a fluid operatedmechanism including a driving motor having a piston provided with headsof differential area mounted to reciprocate within cylinders of adiHerent crosssection, and which piston is connected with 'i an oil wellpump of any suitable or desirable construction, the smaller of .whichpiston heads is adapted to be driven downwardly by means of anon-compressible fiuid under pressure derivedv from the "surface of thewell to drive the pump. plunger downwardly, and which piston is drivenupwardly by the static pressure of the column of fluid being elevatedfrom the well exerting its pressure upon the head of said piston oflarger diam-` eter as the pressure is dissipated from thenorlil-compressible fluid at the surface of the we Other objects andadvantages of this in-f vention it is believed will' be apparent fromthe followin detailed description of a preferred emboi the accompanyingdrawing. l -In the drawing:

Figure 1 is a side elevation partly in section of a fluid operated pumpembodying my invention.

Figure 2 is aQ fragmental sectional eleva v tion thereof.

Figure 3 is an enlarged fragmental section of the pressure relief valveembodied m my inventlon. V

Figure 4 is a sectional end elevation taken substantially on the line4-4 of Figure 2.

Figure 5 is' an end.` sectional view taken substantially on the line 5-5of Figure 2.

Figure 6 is a sectional side elevation of the modified form of fluidoperated pump embodied in my invention.

In the preferred embodiment of my invention illustrated in Figures 1 to5 of thedrawing, 1 indicates a casing which extends ment thereof asillustrated in downwardly from the surface of the well to the oilstrata. l e

Mounted concentrically within the casing 1 is a water or relativelynon-compressible Huid `tube'2 which-extends downwardly in the casofvs'rhichyis secured. an 4 oflarger diameter., v

the tubing 2 is a cylinder 3, hereinafter termed the down-pressurecylinder, to the lower end 11p-pressure cylinder f k"Secured to thelower end of the cylinder/4 i is a packing assembly 5 which is packedoutwardly against the lnner periphery of the casing 1 to close the oilpassage 6 formed within the casing 1 on the outside of the cylinders 3and 4 and tubing 2 above the packing 5. Secured to the lower end ofthecylinder 4 by any suitable means as indicated at 7 is a pump barrel 8which extends through the packing 5 into the fluid to be elevated fromwithin the well. The pump barrel 8 carries the customary standing valve9 at its lower end and yis fitted with a reciprocating plunger 10. Theplunger 10 is connected as indicated at 11 with a connecting rod 12, the

opposite end of which is secured to a pistonk 13. The piston 13 isprovided at its opposed' ends with piston heads 14 and l5 ofdifferential diameter, the upper vpiston head 14 mounted within thewater cylinder 3 being less in cross-section area than the lower pistonhead 15 mounted within the oil cylinder 4.

The casing 1 is provided at its upper end with a casing head 16 throughwhich the tube 2 extends through a packing gland 17 and which isprovided with an oil discharge'pipe 18 through rwhich the oil elevatedfrom the y well is discharged.

' The pipe 2 is filled with a non-com ressible iuid, such, for example,as water, rom the level of the piston head 14 to the priming tube 51.The oil passage 6 is filled with the wellfluid which it is desired topump to the 'surface of the well. The area of the oil piston head 15being greater than the area of the water piston head 14, the totalpressures are regulated so that the piston 13 will at all times remainin elevated position in the cylinders 3 and 4 when there is noadditional pressure exerted upon the water or non-compressible fluid inthe'pipe 6.-

The static pressure of the oil within the oil passage 6 communicateswith the under side of the oil pistonhead 15 through ports -19 formedthrough the oil cylinder 4 below the piston head 15. The ports 19 alsoprovide passagesA for the delivery of oil or fluid being elevated fromthe well into the passage 6as the Huid is elevated from the pumpcylinder 8 by means of the pump plunger 10. The pump plunger l() carriesa working valve 20 and is a hollow plunger.

The lunger 10 rising in its barrel 8 causes oil or diiid from the wellto be drawn in by the standing valve 9 as the pressure within the barrel8 is reduced below the pressure of the oil or fluid in the oil strata.As the plunger 10 is raised the valve 20 seats. As

the plunger 10 is lowered, the standing valve 9 is seated andthe workingvalve 20 rises' \er and by the working valve 2O to a position above theworking valve 20.,"

As the plunger'lO is again raised, the oil above the working valve 20 israised upwardly and is caused to pass i'nto the cylinder 4 from whichitis displaced on the next down stroke of piston 15, therebydisplacing aportionof the oil in the oil passage 6 up through the `oil passage 6and-out of the discharge pipe 18 of the casing head 16.

The plunger 10 1s reciprocated to cause this pumping or raising'of theoil from the barrel 10 as follows:

, As the total pressure exerted against the oil head 15 of the piston 13is greater than the total pressure of the water exerted against rthepiston head 14 of the piston 13 due to the difference' in area, the.piston 13 will at all times tend to assume an elevated position raisingthe plunger 10 in the barrel 8.

In order to drive the plunger 10 downwardly in the barrel 8, pressure isexerted on the water in thetube 2 and against the piston head 14 of thepiston 13 in excess of the pressure exerted against the oil head 15 ofthe piston 13. This increase in pressure is caused by means of a piston21 mounted within the upper section of the tube 2 and caused to movedown therein by means of a. piston head 22 mounted within a surfacepower cylinder 23. Pressure is intermittently exerted on the uppersurface of the piston 22 in the power cylinder I23 by any suitable ordesirable means such, for example, as by means of pressure derived` fromany suitable source of fluid under pressure through a conduit 24 inwhich a three-way valve 25 is mounted. The conduit 24 is coupled withthe power cylinder 23 above the piston 22 so that when the control valve25 is opened, the fluid under pressure from the conduit 24 exerts itspressure on the piston 22 in the powei` cylinder 23, causing the piston22 to be forced downwardly, thereby exerting a pressure upon the Wateror noncompressible Huid in the column 2. This pressure is immediatelytransmitted to the water piston head 14 causing the plunger 13 to bedriven downwardly. In order to release the pressure from the water head14 to allow the static pressure of the fluid in the column 6 to exert apressure on the head 15 in excess of the pressure exerted on the head14, the fluid pressure imposed upon the piston 22'is relieved through anexhaust conduit 26 connected to the three-way valve 25. As the pressureis thus released, the piston 131 rises, raisingvthe plunger 10 in thebarre 8.

In order to automatically control the action of the piston 22, thethree-way control valve 25 is provided with an actuating arm 27 which iscoupled to triggers 28 and 29 mountface of the pistonengages the trigger29 which is connected through a link 30 with the arm 27, causing thevalve 25 to be rotated to a position to establish communication betweenthe exhaust conduit 26 and the power c `linder 23, resulting in thefluid compressed a ove the piston 22 being relieved either into theatmosphere or a conduit under reduced pressure. `rlhe iston 22 is thenmoved upwardly by the static pressure of the fluid within the passage 6exerting its pressure against the larger piston head 15 until the piston22 engages the trigger 28. :The trigger 28 is connected through a pairof links 31 and 32 to a connecting rod 33 which is in turn connectedwith the arm 27. As the trigger 28 is pushed outwardly, the valve 1srotated to a position to open the conduit 24 to the ,power cylinder 23permitting the fluid under pressure from the conduit 24 to exert itspressure downwardly on the piston 22, thereby driving the piston 13, andhence the plunger 10, downwardly.

Formed above the piston head 15 when the piston head 15 is down, in theoil cylinder 4, is a chamber 34. As the piston head 15 is caused to movedownwardly by the pressure s of the fluid exerted against the pistonhead 14, the chamber 34 increases in volume, resulting in theestablishing within the chamber 34 of a rfegion of reduced pcressure.

As pumps of the class here under consideration are many times utilizedfor the raising of liquids containing sand and other foreign matter tothe surface of the well, I prefer to provide a means whereby this sandor foreign matter may be carried out with a circulatin culation, providemeans for circulating fluid from the surface of the well through themechanism and back to the surface H"of the well.

To accomplish this I form the piston 13 hollow and mount at the upperend ofv the piston 13 a pressure control valve 35 which opens only lwhenthe pressure withinthe cylinder 3 exceeds a cert-ain given pressure. Thepressure valve 35 may be of any suit'- able or desirable constructionand is herein illustrated as of the type including a disc head 36provided Wit a valve stem 37 carried in aV bushing or lve cage 38screwthreaded as indicated at 39 into the upper cylindrical extension 40of the piston 13.

The valve stem 37 carries a stop 41 at its upper end and the valve cage38 is provided with a bridge 42 spaced from the stop 31. Mounted aroundthe valve stem 37 between the stop 41 and the bridge 42 is a spring. 43

fluid. In order to obtain the cir-- the tension of the spring 43. Formedat the lower end of the hollow piston 13 below the piston head 15 are aplurality of ports 44 through which the liquid passing the pressurevalve 36 passes when the pressure in the cylinder 3 exceeds apredetermined' amount. The fiuidthus finding its way through the ports44 passes through'the ports 19 to wash the ports 19 clean of yaccumulated sand or foreign matter carried by the oil and is circulatedup through the passage 6 to clean the passage 6 of sand or accumulated`foreign matter. The fluid is circulated from the surfacev of the wellby coupling a circulating pump (not shown) to the priming nip-ple 51 toforcev a circulating fluid through tube 2, cylinder 3, piston 13, ports44 and 19back through passage 6 to the surface of the well and outdischarge pipe 18.

Each of the piston heads 14 and 15 is formed of a packing cup 45 whichvis seated on a disc 46 mounted on a shoulder formed on the 'piston 13and the packing cups 45 are'held in position by means of packing discs47 forced against the packing cups by means of packing followers 48which are threaded to 'the' respective fends of the piston 13: Packingcups 45 are each turned in a direction toward the source of pressureagainst I the respective ,packing heads 14 and 15, so that the pressureexerted on the heads 14 and 15 tends to expand thel packing cups-outwardly. 4

In order to stop the piston'` 13 on its downward stroke as an excesspressure is utilized in the cylinder 3 to open the valve 36, .a`

stop bridge 49 is mounted at thel lower end of the oil cylinder 4toengage the packing follower 48 ofl the vpiston head 15. The bridge 49 isprovided at points spaced around its upper surface with raised stops 50holding the packing follower 48 from seating tightly f way into thechamber'34 must be dispelled therefrom or there is a possibility thatthe device will become fluid-locked. In orderto insure the dispelling ofthe fluid from the chamber 34, I propose to operate the device asfollows:

The pressure exerted on the larger piston head 15 by the static head-ofthe fluid within the passage 6-due to the increased area of the head 15over the head 14 must be sufficient to give to the piston assembly 13`during its upto carry .the piston assembly 13 the full length of thecylinder 4 until the piston head 15 stops against 'the lower end -of thesmaller cylinder 3. The fluid in the chamber-34, which has found its waythereto by leakage, will be forced,v out of the chamber 34around thepiston heads 14 or 15. This scavenging of the chamber 34/is caused bythe relatively high pressure exerted yagainst this fluid in the vchamber34 due to the inertia of the moving mass of the piston 13 and the columnof fluid in the passage 6 as the piston head 15 `engages the fluid inthe chamber 34. The packing cups are turned toward the respectivecolumns of fluid in the casing 1 and pipe 2 and away from the chamber 34and lwill open more easily from a high pressure barrel 8a.

piston 13a and hence the plun er 10a to its elevated position. As in therst modificazoi tion of my invention, I prefer to employ wav ter or asimilar non-compressible fluid inthe conduit 2a so that aspressure isexerted upon the water or non-compressible fluid, the pressure impulseis immediately transmitted to. the piston 13a and not taken up by thecompressibility of the fluid in the column 2a.

Having fully described ymy invention, it is to be understood that I donot `wish to be limited to the details herein set forth, but` myinvention is of the full scope ofv the lappended claims. f'

within the chamber 34, permitting the fluid J I claim:

within the chamber 34 to be squeezed out of the chamber 34 by theinertia of the movingv piston 13 and column of fluid in the passagebefore the piston 13 is brought to rest mechanically against the lowerend of the cylinder 3.

In the modified form of my invention illustrated in -Figure 6, likepart'sare numbered with the same numerals with the addition of anexponent a.

In this modification of my invention n0 differential area pistons areemployed but the oil in the column 6a at the bottom of the well ismaintained under a substantially constant pressure in excessof itsstatic pressure by. any suitable or desirable means, this substanvtially constant pressure being in excess of the static pressure of thecolumn of water in the tube 2a. The piston 13a isvconnected byv means ofa rod 12a with the pump plunger 10a mounted in the barrel 8a in the samemanner as in the modification heretofore dei scribed. The tube, 2aextends through the control head 16a and into a power cylinder 23a inwhich a piston 22a is mounted. Piston 22a is forced downwardly by meansof pressure applied to its -upper surface through .any suitable ordesirable means which may be similar -to thatdisclosed in the firstmodification of my invention heretofore described. The oil being pumpedonto the passage 6a is maintained under a constant pressure in,

excess of its static head' by any suitable or desirable means such, forexample, as by having the discharge pipe 18a dischargev the oil.

elevated from -the well through a pressure valve.

In the modification of my invention shown in Figure 6, vthe pressure ofthe oil in the column 6a exerted against the underside of the piston 13atends to raise the plunger 10a to its`elevated positi 1i. As pressure isimposed upon the top of the piston 13a in exfcessfof .the pressure inthe column 6a by the development of pressure above the piston 22a, thepiston 13a is forced downwardly to exerted by the lattersaid column 4offlui on the upper side of said piston, and meansv under side of saidpiston, the static pressure of a column of fluid in the pipe beingexerted against the upper side of said piston, means for intermittentlyincreasing the pressure t exerted by the latter said column of fluid,lon the upper side of saidspistom'andmeansl carried by the piston forclosing theI passage therethrough operable when the pressure ofl thefluid inthe pipe exceeds a given amountA to permit said fluid to passthrough said piston and circulate through the cylinder. and out throughsaid casing.

2. In a vdevice of the class `described the pir@ combination of avertically extending casing, Y.

a pipe mounted concentrically within the casing, a fluid motor includinga cylinder mounted within the casing and connected to said pipe, ahollow piston operatively mounted in said cylinder, means mounted insaid fluid motor for limiting the downward travel of said piston, meansfor venting the cylinder below the piston into the casing, a pumpmounted within the casing below said cylinder and including a pumpplunger, means connecting the pump plunger with the iston, the staticpressure of the column of fllflid 1n the casmg bemg exerted on the underside of said piston, the static pressure ofthe coll umn of liquid in thepipe being exerted agamst the upper side of said piston, means forintermittently increasing the pressur carried by the piston for closingthe passage therethrough operable when the pressure' of the fluid in thei1pipe exceeds a given amount to permit said uid to pass through saidpis- 5 ton and circulate throughv the cylinder and out through saideasing.

Signed at Los Angeles, California, this 15th day of November, 1930. l

v ROBERT H. THOMPSON.

